Sources, properties and uses detergents and soaps Structure, their mode and action. Fats and oils belong to a general group of compounds known as lipids. SOURCES Fats are solids that usually come from animals e.g. Tallow (mutton fat). Oils are liquids that come from plants e.g. vegetable oil, coconut oil etc. Both fat and oil…
ALKANOATES General molecular formula, nomenclature, preparation, properties and uses. SOURCES The alkanoic acid or carboxylic acids are also called fatty acids because some of them are found in natural fats and oils. They contain the functional group called carboxy group. NOMENCLATURE The IUPAC name of each homologue is obtained by changing the “-e”…
SOURCES OF ALKANOLS – From destructive distillation wood. – From starchy food and sugar General molecular formular Alkanol is a homologous series with general molecular formular of Cn H2n+1OH or ROH. Or (CnH2n+2O). Nomenclature The names of alkanols are obtained by substituting “e” in alkanes with “Ol” in alkanol e.g. methanol (CH3OH), ethanol…
Benzene: Benzene is a typical aromatic compound with molecular formula of C6H6. It has the structure of: Preparation From coal tar: The destructive distillation of coal produced coal tar which contain benzene From petreoleum; The dehydrogenated of alkane using valladim (v) oxide (v2O5) as catalyst at 500oC and 20 atmos give benzene C6H14 V2O2C6H6 + …
Alkynes are the homologous series of unsaturated hydrocarbon with a general molecular formua CnH2n-2. Alkynes show a high degree of unsaturation than alkenes, hence,t hey are chemically more reactive than the corresponding alkenes or alkanes. Examples are : H H – C = C – H HC – C = C- H [ Ethyne. …
UNSATURATED HYDROCARBONS These are hydrocarbons in which carbon atoms join with each other by multiple bonds. The multiple bond can be double bonds e.g Alkene or triple bonds e.g Alkyne. Ethene2 .Ethyne H – C = C – H H – C = C – H H H. Alkenes e.gEthene Nomenclature The process of naming…
Saturated Hydrocarbons Saturated hydrocarbons are hydrocarbons consisting of carbon chains with single bond between them in which carbon joins with another carbon by single covalent bond e.g Alkanes ( like ethane C2H6, propane C3H8 ) H H HHH H – C C – H H – C – C – C – H…
Definition of Simple Machine A machine is a tool or device that makes work easier. It is defined as a tool which uses force applied (effort) at one point to overcome another resisting force (effort) at another point. Examples of machine include: a plier, the human arm, a gear, a pulley etc. Types of…
Percentage of Oxygen in Air We have read that Air consists mainly of molecules of oxygen and nitrogen with important yet trace amounts of other gases. We know that the combustion of organic material requires oxygen. The idea here is to capture a quantity of air in a measured and isolated volume and then use…
Alkali is pronounced like alcohol, with ‘lie’ at the end instead of ‘hol’. An alkali is any substance which produces OH– ions in water. OH– ions are called hydroxide ions. If there are excess of (OH)– ions when a compound is dissolved in water, the solution is called a base or an alkaline solution. A base…
WHAT IS ACIDS, BASES AND INDICATORS? All the elements in nature fall into three classes: metals, non-metals and gases. Non-metals are also sometimes called metalloids. The compounds formed by combination of the elements can also be classified as organic and inorganic compounds. Organic compounds are formed from a combination of carbon and hydrogen; they are…
EVAPORATION AND BOILING (LIQUID TO GAS) On heating particles gain kinetic energy and move faster. In evaporation and boiling the highest kinetic energy molecules can ‘escape’ from the attractive forces of the other liquid particles. The particles lose any order and become completely free to form a gas or vapour. Energy is needed to overcome…
Chemists are the people who transform the everyday materials around us into amazing things. Some chemists work on cures for cancer while others monitor the ozone protecting us from the sun. Still others discover new materials to make our homes warmer in the winter, or new textiles to be used in the latest fashions. The…
Sodium Carbonate (Na2CO3) Popularly known as washing soda or soda ash, sodium carbonate is a commercially important compound. In earlier days, it was obtained from the ash of plants and from natural deposits in India and Egypt. Manufacture of Sodium Carbonate Raw Materials Sodium chloride – NaCl (brine solution) Ammonia – NH3 Limestone –…
What is Carbon monoxide?. Carbon monoxide is an odourless, tasteless and colourless gas, which is insoluble in water. It is extremely poisonous. Under no circumstances must the gas be inhaled or smelled. It is not usually prepared in a school laboratory. If need be, the gas should be prepared in a fume chamber. Preparation…
CHEMICAL PROPERTIES OF CARBON The combustion of carbon: Carbon reacts with oxygen to form two oxides, carbon dioxide, CO2, and carbon monoxide CO. The proportions of these two oxides formed during combustion depend on the conditions. At about 500 ºC, carbon dioxide is produced almost exclusively, provided that oxygen is in excess: C(s) + O2(g)…
AMORPHOUS CARBON Apart from diamond and graphite, which are crystalline forms of carbon, all other forms of carbon are amorphous allotropes of carbon. Coke Coke is the amorphous allotrope of carbon, which is derived from coal. When coal undergoes destructive distillation, it yields two allotropes of carbon, namely coke and gas carbon. Destructive distillation is…
What is graphite? Unlike the tetrahedral arrangement of atoms in diamond, the carbon atoms in graphite are arranged in the form of hexagonal rings in layers (Fig.10.2). Each carbon is bonded to only three other carbon atoms in that layer. Different layers of graphite are held together by rather weak forces. Hence they can slide…
DIAMOND What is diamond? Diamond is the purest form of natural carbon. It occurs as small crystals embedded in rocks. These are supposed to have been formed by the crystallization of carbon under extreme pressure and temperature in the interior of the earth. Nowadays, synthetic industrial diamonds are being manufactured by subjecting graphite to very…
Cathode reactions (reduction) (-) negative cathode where reduction of the attracted positive cations is by electron gain (reduction) to form metal atoms or hydrogen [from Mn+ or H+, n = numerical charge]. The electrons come from the positive anode. Hydrogen ions are reduced to hydrogen gas molecules. Electrolysis of many dilute salts or acid solutions…